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therapy (RT) and concomitant temozolomid (TEM) followed by adjuvant TEM. TEM, oral alkylating agent, has shown promising activity in last ten years in the treatment of glioblastoma. Our aim was to examine the benefit of concomitant therapy involving radiotherapy and temozolomide in clinical practice. Material and Methods The study was retrospective / prospective and included the total of 113 patients with GBM diagnosis. Each patient was ECOG0 and ECOG1 performance status. Among that number, 47 patients received postoperative radiotherapy and 66 patients received concomitant temozolomide plus 3D conformal radiotherapy plus adjuvant temozolomid. Results The mean value of overall survival in patients who received only postoperative radiotherapy was 9.93 months, compared to statistically longer overall survival in the group of patients who received chemoradiotherapy (13.89 months) (p=0.006). Furthermore, chemoradiotherapy group has been divided into two subgroups, one consisted of patients who received complete 6 cycles of chemotherapy with temozolomide, and second who received uncompleted treatment (5 ≤ cycles). Statistically significant longer overall survival was registered in the first subgroup (16.17 months) as compared to the second (12.08 months) (p=0.006).

A Mann-Whitney U test revealed a difference in the median interval from surgery to SRS of patients with cavities with local control and local failure (6 vs 8 weeks, U = 344, z= 1.9, p= .052). A Fisher’s exact test for independence indicated an association approaching statistical significance between patients with cavities who received SRS less than or more than 7 weeks post operatively and local recurrence. Patients with a longer wait were more likely to experience Local recurrence (60%) than those who were treated within 7 weeks of surgery (40%), p = 0.051. Patients with a margin less than 2mm were more likely to experience local recurrence (67%) than those with margin = 2mm (33%), p = 0.059. We separately reviewed patients who received post operative WBRT pre SRS. None of these patients had local or distant failure (5 patients, 6 cavities). There was no statistically significant difference in OS for patients with or without WBRT pre SRS; 22.7 months vs 20.2. Conclusion Median OS (95% CI) for our patient group was 22.7 (14.5– 30.8) months (fig.1), with a local control rate of 69%. The only variables approaching statistical significance in terms of influencing LC were margin size (<2 vs. =2mm), interval from surgery to SRS (< 7/52 vs. >7/52) and presence or not of additional in-situ metastases. Regarding patients that received WBRT and SRS boost there was no difference in OS, compared to SRS alone. EP-1194 Benefit of adjuvant temozolomid chemoradiotherpy in GBM: provocative results or potential bias I. Djan 1,2 , S. Salma 3 , M. Lucic 2,4 , D. Tesanovic 1,2 , A. Morganti 5 1 Institute of Oncology Vojvodina, Radiotherapy Department, Sremska Kamenica, Serbia 2 University of Novi Sad, Faculty of Medicine, Novi Sad, Serbia 3 Institute of Oncology Vojvodina, Medical Oncology Department, Sremska Kamenica, Serbia 4 Institute of Oncology Vojvodina, Diagnostics and Imaging Center, Sremska Kamenica, Serbia 5 Università di Bologna- Radiation Oncology Center, Department of Experimental- Diagnostic and Specialty Medicine - DIMES, Bologna, Italy Purpose or Objective Adult glioblastoma (GBM) is one of the most deadly of all malignant solid tumors. The current standard of care is maximal safe surgical resection, followed by radiation

Conclusion The benefit from the concomitant usage of temozolomide and radiotherapy was proved, and statistically significant difference among groups and subgroups were observed regarding overall survival. EP-1195 Hypofractionated stereotactic radiotherapy (HFSRT) for 50 brain metastases: Institutional experience R. Ciervide 1 , M. López 1 , O. Hernando 1 , E. Sánchez 1 , A. Montero 1 , J. Valero 1 , M. García-Aranda 1 , X. Chen 1 , R. Alonso 1 , B. Alvarez 1 , A. Acosta 1 , C. Rubio 1 1 Hospital Universitario Madrid Sanchinarro - Grupo Hospital de Madrid, Radiation Oncology depatment, Madrid, Spain Purpose or Objective Stereotactic radiosurgery (SRS) is a therapeutic tool to treat brain metastases that is increasingly being used as a